Students of the Park Slope Rock School wait before performing on stage at La Bellevilloise concert hall in Paris. [Photo/Agencies]

'It's cool, Dad'

It also helps that many rock standards have only three chords, though as Domnarski says, "it is all about how you play them".

The experience has also turned the usual parent-child relationships on their head.

"I admit I'm scared," says Chabert-Marcon, an Internet company boss. "But my kids who have done it all before keep telling me, 'Dad, it's fine, you'll see.'"

Bass player Luc Heinrich, a complete musical novice, knew he was hitting the groove when his son winked at him as he passed the bedroom door as he practised. "That was priceless," he says.

The same basic rules apply for children and adults, Domnarski insists. "It is about working as a team and sharing ideas and learning how to power through the nerves to get on stage and perform in front of hundreds of people. It's an amazing experience."

For Langlois and the others, playing in a band has been a revelation. "I have tried to be a runner three or four times, but I never got the runner's high.

"But doing this gets the adrenaline pumping and that emotional connection back to your teenage years, to goofing with the cassette recorder with your friends," he says.

"You put that all away when you become an adult. When you get to be 40, you say 'OK, I am never going to be Madonna, I'm never going to the Olympics, and it's all kids and school and downhill from here.' But it doesn't need to be like that..."